X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fconsumer.c;h=8806e9c322bef43b818975bee8f44bc520e3aa53;hp=57b5b19d17db507b6b42d5407be7535512236e1e;hb=a4baae1b0463bc4ce65c2a458c4a941e7fabc594;hpb=7972aab22f74b18faa168c0482216a3dd711a075

diff --git a/src/bin/lttng-sessiond/consumer.c b/src/bin/lttng-sessiond/consumer.c
index 57b5b19d1..8806e9c32 100644
--- a/src/bin/lttng-sessiond/consumer.c
+++ b/src/bin/lttng-sessiond/consumer.c
@@ -28,10 +28,100 @@
 #include <common/common.h>
 #include <common/defaults.h>
 #include <common/uri.h>
+#include <common/relayd/relayd.h>
 
 #include "consumer.h"
-#include "health.h"
+#include "health-sessiond.h"
 #include "ust-app.h"
+#include "utils.h"
+
+/*
+ * Send a data payload using a given consumer socket of size len.
+ *
+ * The consumer socket lock MUST be acquired before calling this since this
+ * function can change the fd value.
+ *
+ * Return 0 on success else a negative value on error.
+ */
+int consumer_socket_send(struct consumer_socket *socket, void *msg, size_t len)
+{
+	int fd;
+	ssize_t size;
+
+	assert(socket);
+	assert(socket->fd_ptr);
+	assert(msg);
+
+	/* Consumer socket is invalid. Stopping. */
+	fd = *socket->fd_ptr;
+	if (fd < 0) {
+		goto error;
+	}
+
+	size = lttcomm_send_unix_sock(fd, msg, len);
+	if (size < 0) {
+		/* The above call will print a PERROR on error. */
+		DBG("Error when sending data to consumer on sock %d", fd);
+		/*
+		 * At this point, the socket is not usable anymore thus closing it and
+		 * setting the file descriptor to -1 so it is not reused.
+		 */
+
+		/* This call will PERROR on error. */
+		(void) lttcomm_close_unix_sock(fd);
+		*socket->fd_ptr = -1;
+		goto error;
+	}
+
+	return 0;
+
+error:
+	return -1;
+}
+
+/*
+ * Receive a data payload using a given consumer socket of size len.
+ *
+ * The consumer socket lock MUST be acquired before calling this since this
+ * function can change the fd value.
+ *
+ * Return 0 on success else a negative value on error.
+ */
+int consumer_socket_recv(struct consumer_socket *socket, void *msg, size_t len)
+{
+	int fd;
+	ssize_t size;
+
+	assert(socket);
+	assert(socket->fd_ptr);
+	assert(msg);
+
+	/* Consumer socket is invalid. Stopping. */
+	fd = *socket->fd_ptr;
+	if (fd < 0) {
+		goto error;
+	}
+
+	size = lttcomm_recv_unix_sock(fd, msg, len);
+	if (size <= 0) {
+		/* The above call will print a PERROR on error. */
+		DBG("Error when receiving data from the consumer socket %d", fd);
+		/*
+		 * At this point, the socket is not usable anymore thus closing it and
+		 * setting the file descriptor to -1 so it is not reused.
+		 */
+
+		/* This call will PERROR on error. */
+		(void) lttcomm_close_unix_sock(fd);
+		*socket->fd_ptr = -1;
+		goto error;
+	}
+
+	return 0;
+
+error:
+	return -1;
+}
 
 /*
  * Receive a reply command status message from the consumer. Consumer socket
@@ -47,18 +137,12 @@ int consumer_recv_status_reply(struct consumer_socket *sock)
 
 	assert(sock);
 
-	ret = lttcomm_recv_unix_sock(sock->fd, &reply, sizeof(reply));
-	if (ret <= 0) {
-		if (ret == 0) {
-			/* Orderly shutdown. Don't return 0 which means success. */
-			ret = -1;
-		}
-		/* The above call will print a PERROR on error. */
-		DBG("Fail to receive status reply on sock %d", sock->fd);
+	ret = consumer_socket_recv(sock, &reply, sizeof(reply));
+	if (ret < 0) {
 		goto end;
 	}
 
-	if (reply.ret_code == LTTNG_OK) {
+	if (reply.ret_code == LTTCOMM_CONSUMERD_SUCCESS) {
 		/* All good. */
 		ret = 0;
 	} else {
@@ -88,25 +172,20 @@ int consumer_recv_status_channel(struct consumer_socket *sock,
 	assert(stream_count);
 	assert(key);
 
-	ret = lttcomm_recv_unix_sock(sock->fd, &reply, sizeof(reply));
-	if (ret <= 0) {
-		if (ret == 0) {
-			/* Orderly shutdown. Don't return 0 which means success. */
-			ret = -1;
-		}
-		/* The above call will print a PERROR on error. */
-		DBG("Fail to receive status reply on sock %d", sock->fd);
+	ret = consumer_socket_recv(sock, &reply, sizeof(reply));
+	if (ret < 0) {
 		goto end;
 	}
 
 	/* An error is possible so don't touch the key and stream_count. */
-	if (reply.ret_code != LTTNG_OK) {
+	if (reply.ret_code != LTTCOMM_CONSUMERD_SUCCESS) {
 		ret = -1;
 		goto end;
 	}
 
 	*key = reply.key;
 	*stream_count = reply.stream_count;
+	ret = 0;
 
 end:
 	return ret;
@@ -126,24 +205,15 @@ int consumer_send_destroy_relayd(struct consumer_socket *sock,
 	assert(consumer);
 	assert(sock);
 
-	DBG2("Sending destroy relayd command to consumer sock %d", sock->fd);
-
-	/* Bail out if consumer is disabled */
-	if (!consumer->enabled) {
-		ret = LTTNG_OK;
-		DBG3("Consumer is disabled");
-		goto error;
-	}
+	DBG2("Sending destroy relayd command to consumer sock %d", *sock->fd_ptr);
 
 	msg.cmd_type = LTTNG_CONSUMER_DESTROY_RELAYD;
 	msg.u.destroy_relayd.net_seq_idx = consumer->net_seq_index;
 
 	pthread_mutex_lock(sock->lock);
-	ret = lttcomm_send_unix_sock(sock->fd, &msg, sizeof(msg));
+	ret = consumer_socket_send(sock, &msg, sizeof(msg));
 	if (ret < 0) {
-		/* Indicate that the consumer is probably closing at this point. */
-		DBG("send consumer destroy relayd command");
-		goto error_send;
+		goto error;
 	}
 
 	/* Don't check the return value. The caller will do it. */
@@ -151,9 +221,8 @@ int consumer_send_destroy_relayd(struct consumer_socket *sock,
 
 	DBG2("Consumer send destroy relayd command done");
 
-error_send:
-	pthread_mutex_unlock(sock->lock);
 error:
+	pthread_mutex_unlock(sock->lock);
 	return ret;
 }
 
@@ -169,7 +238,7 @@ void consumer_output_send_destroy_relayd(struct consumer_output *consumer)
 	assert(consumer);
 
 	/* Destroy any relayd connection */
-	if (consumer && consumer->type == CONSUMER_DST_NET) {
+	if (consumer->type == CONSUMER_DST_NET) {
 		rcu_read_lock();
 		cds_lfht_for_each_entry(consumer->socks->ht, &iter.iter, socket,
 				node.node) {
@@ -212,7 +281,7 @@ int consumer_create_socket(struct consumer_data *data,
 	socket = consumer_find_socket(data->cmd_sock, output);
 	rcu_read_unlock();
 	if (socket == NULL) {
-		socket = consumer_allocate_socket(data->cmd_sock);
+		socket = consumer_allocate_socket(&data->cmd_sock);
 		if (socket == NULL) {
 			ret = -1;
 			goto error;
@@ -225,6 +294,8 @@ int consumer_create_socket(struct consumer_data *data,
 		rcu_read_unlock();
 	}
 
+	socket->type = data->type;
+
 	DBG3("Consumer socket created (fd: %d) and added to output",
 			data->cmd_sock);
 
@@ -297,18 +368,20 @@ struct consumer_socket *consumer_find_socket(int key,
 /*
  * Allocate a new consumer_socket and return the pointer.
  */
-struct consumer_socket *consumer_allocate_socket(int fd)
+struct consumer_socket *consumer_allocate_socket(int *fd)
 {
 	struct consumer_socket *socket = NULL;
 
+	assert(fd);
+
 	socket = zmalloc(sizeof(struct consumer_socket));
 	if (socket == NULL) {
 		PERROR("zmalloc consumer socket");
 		goto error;
 	}
 
-	socket->fd = fd;
-	lttng_ht_node_init_ulong(&socket->node, fd);
+	socket->fd_ptr = fd;
+	lttng_ht_node_init_ulong(&socket->node, *fd);
 
 error:
 	return socket;
@@ -372,8 +445,8 @@ void consumer_destroy_socket(struct consumer_socket *sock)
 	 * consumer was registered,
 	 */
 	if (sock->registered) {
-		DBG3("Consumer socket was registered. Closing fd %d", sock->fd);
-		lttcomm_close_unix_sock(sock->fd);
+		DBG3("Consumer socket was registered. Closing fd %d", *sock->fd_ptr);
+		lttcomm_close_unix_sock(*sock->fd_ptr);
 	}
 
 	call_rcu(&sock->node.head, destroy_socket_rcu);
@@ -405,8 +478,32 @@ error:
 	return output;
 }
 
+/*
+ * Iterate over the consumer output socket hash table and destroy them. The
+ * socket file descriptor are only closed if the consumer output was
+ * registered meaning it's an external consumer.
+ */
+void consumer_destroy_output_sockets(struct consumer_output *obj)
+{
+	struct lttng_ht_iter iter;
+	struct consumer_socket *socket;
+
+	if (!obj->socks) {
+		return;
+	}
+
+	rcu_read_lock();
+	cds_lfht_for_each_entry(obj->socks->ht, &iter.iter, socket, node.node) {
+		consumer_del_socket(socket, obj);
+		consumer_destroy_socket(socket);
+	}
+	rcu_read_unlock();
+}
+
 /*
  * Delete the consumer_output object from the list and free the ptr.
+ *
+ * Should *NOT* be called with RCU read-side lock held.
  */
 void consumer_destroy_output(struct consumer_output *obj)
 {
@@ -414,19 +511,11 @@ void consumer_destroy_output(struct consumer_output *obj)
 		return;
 	}
 
-	if (obj->socks) {
-		struct lttng_ht_iter iter;
-		struct consumer_socket *socket;
-
-		rcu_read_lock();
-		cds_lfht_for_each_entry(obj->socks->ht, &iter.iter, socket, node.node) {
-			consumer_del_socket(socket, obj);
-			consumer_destroy_socket(socket);
-		}
-		rcu_read_unlock();
+	consumer_destroy_output_sockets(obj);
 
+	if (obj->socks) {
 		/* Finally destroy HT */
-		lttng_ht_destroy(obj->socks);
+		ht_cleanup_push(obj->socks);
 	}
 
 	free(obj);
@@ -434,12 +523,13 @@ void consumer_destroy_output(struct consumer_output *obj)
 
 /*
  * Copy consumer output and returned the newly allocated copy.
+ *
+ * Should *NOT* be called with RCU read-side lock held.
  */
 struct consumer_output *consumer_copy_output(struct consumer_output *obj)
 {
+	int ret;
 	struct lttng_ht *tmp_ht_ptr;
-	struct lttng_ht_iter iter;
-	struct consumer_socket *socket, *copy_sock;
 	struct consumer_output *output;
 
 	assert(obj);
@@ -456,27 +546,63 @@ struct consumer_output *consumer_copy_output(struct consumer_output *obj)
 	/* Putting back the HT pointer and start copying socket(s). */
 	output->socks = tmp_ht_ptr;
 
+	ret = consumer_copy_sockets(output, obj);
+	if (ret < 0) {
+		goto malloc_error;
+	}
+
+error:
+	return output;
+
+malloc_error:
+	consumer_destroy_output(output);
+	return NULL;
+}
+
+/*
+ * Copy consumer sockets from src to dst.
+ *
+ * Return 0 on success or else a negative value.
+ */
+int consumer_copy_sockets(struct consumer_output *dst,
+		struct consumer_output *src)
+{
+	int ret = 0;
+	struct lttng_ht_iter iter;
+	struct consumer_socket *socket, *copy_sock;
+
+	assert(dst);
+	assert(src);
+
 	rcu_read_lock();
-	cds_lfht_for_each_entry(obj->socks->ht, &iter.iter, socket, node.node) {
+	cds_lfht_for_each_entry(src->socks->ht, &iter.iter, socket, node.node) {
+		/* Ignore socket that are already there. */
+		copy_sock = consumer_find_socket(*socket->fd_ptr, dst);
+		if (copy_sock) {
+			continue;
+		}
+
 		/* Create new socket object. */
-		copy_sock = consumer_allocate_socket(socket->fd);
+		copy_sock = consumer_allocate_socket(socket->fd_ptr);
 		if (copy_sock == NULL) {
 			rcu_read_unlock();
-			goto malloc_error;
+			ret = -ENOMEM;
+			goto error;
 		}
 
 		copy_sock->registered = socket->registered;
+		/*
+		 * This is valid because this lock is shared accross all consumer
+		 * object being the global lock of the consumer data structure of the
+		 * session daemon.
+		 */
 		copy_sock->lock = socket->lock;
-		consumer_add_socket(copy_sock, output);
+		consumer_add_socket(copy_sock, dst);
 	}
 	rcu_read_unlock();
 
 error:
-	return output;
-
-malloc_error:
-	consumer_destroy_output(output);
-	return NULL;
+	return ret;
 }
 
 /*
@@ -504,6 +630,12 @@ int consumer_set_network_uri(struct consumer_output *obj,
 		if (uri->port == 0) {
 			/* Assign default port. */
 			uri->port = DEFAULT_NETWORK_CONTROL_PORT;
+		} else {
+			if (obj->dst.net.data_isset && uri->port ==
+					obj->dst.net.data.port) {
+				ret = -LTTNG_ERR_INVALID;
+				goto error;
+			}
 		}
 		DBG3("Consumer control URI set with port %d", uri->port);
 		break;
@@ -513,11 +645,18 @@ int consumer_set_network_uri(struct consumer_output *obj,
 		if (uri->port == 0) {
 			/* Assign default port. */
 			uri->port = DEFAULT_NETWORK_DATA_PORT;
+		} else {
+			if (obj->dst.net.control_isset && uri->port ==
+					obj->dst.net.control.port) {
+				ret = -LTTNG_ERR_INVALID;
+				goto error;
+			}
 		}
 		DBG3("Consumer data URI set with port %d", uri->port);
 		break;
 	default:
 		ERR("Set network uri type unknown %d", uri->stype);
+		ret = -LTTNG_ERR_INVALID;
 		goto error;
 	}
 
@@ -553,6 +692,7 @@ int consumer_set_network_uri(struct consumer_output *obj,
 		}
 		if (ret < 0) {
 			PERROR("snprintf set consumer uri subdir");
+			ret = -LTTNG_ERR_NOMEM;
 			goto error;
 		}
 
@@ -564,7 +704,7 @@ int consumer_set_network_uri(struct consumer_output *obj,
 equal:
 	return 1;
 error:
-	return -1;
+	return ret;
 }
 
 /*
@@ -578,10 +718,10 @@ int consumer_send_fds(struct consumer_socket *sock, int *fds, size_t nb_fd)
 	assert(sock);
 	assert(nb_fd > 0);
 
-	ret = lttcomm_send_fds_unix_sock(sock->fd, fds, nb_fd);
+	ret = lttcomm_send_fds_unix_sock(*sock->fd_ptr, fds, nb_fd);
 	if (ret < 0) {
 		/* The above call will print a PERROR on error. */
-		DBG("Error when sending consumer fds on sock %d", sock->fd);
+		DBG("Error when sending consumer fds on sock %d", *sock->fd_ptr);
 		goto error;
 	}
 
@@ -601,13 +741,9 @@ int consumer_send_msg(struct consumer_socket *sock,
 
 	assert(msg);
 	assert(sock);
-	assert(sock->fd >= 0);
 
-	ret = lttcomm_send_unix_sock(sock->fd, msg,
-			sizeof(struct lttcomm_consumer_msg));
+	ret = consumer_socket_send(sock, msg, sizeof(struct lttcomm_consumer_msg));
 	if (ret < 0) {
-		/* The above call will print a PERROR on error. */
-		DBG("Error when sending consumer channel on sock %d", sock->fd);
 		goto error;
 	}
 
@@ -627,18 +763,12 @@ int consumer_send_channel(struct consumer_socket *sock,
 
 	assert(msg);
 	assert(sock);
-	assert(sock->fd >= 0);
 
-	ret = lttcomm_send_unix_sock(sock->fd, msg,
-			sizeof(struct lttcomm_consumer_msg));
+	ret = consumer_send_msg(sock, msg);
 	if (ret < 0) {
-		/* The above call will print a PERROR on error. */
-		DBG("Error when sending consumer channel on sock %d", sock->fd);
 		goto error;
 	}
 
-	ret = consumer_recv_status_reply(sock);
-
 error:
 	return ret;
 }
@@ -653,6 +783,7 @@ void consumer_init_ask_channel_comm_msg(struct lttcomm_consumer_msg *msg,
 		int overwrite,
 		unsigned int switch_timer_interval,
 		unsigned int read_timer_interval,
+		unsigned int live_timer_interval,
 		int output,
 		int type,
 		uint64_t session_id,
@@ -663,7 +794,12 @@ void consumer_init_ask_channel_comm_msg(struct lttcomm_consumer_msg *msg,
 		uint64_t relayd_id,
 		uint64_t key,
 		unsigned char *uuid,
-		uint32_t chan_id)
+		uint32_t chan_id,
+		uint64_t tracefile_size,
+		uint64_t tracefile_count,
+		uint64_t session_id_per_pid,
+		unsigned int monitor,
+		uint32_t ust_app_uid)
 {
 	assert(msg);
 
@@ -676,20 +812,28 @@ void consumer_init_ask_channel_comm_msg(struct lttcomm_consumer_msg *msg,
 	msg->u.ask_channel.overwrite = overwrite;
 	msg->u.ask_channel.switch_timer_interval = switch_timer_interval;
 	msg->u.ask_channel.read_timer_interval = read_timer_interval;
+	msg->u.ask_channel.live_timer_interval = live_timer_interval;
 	msg->u.ask_channel.output = output;
 	msg->u.ask_channel.type = type;
 	msg->u.ask_channel.session_id = session_id;
+	msg->u.ask_channel.session_id_per_pid = session_id_per_pid;
 	msg->u.ask_channel.uid = uid;
 	msg->u.ask_channel.gid = gid;
 	msg->u.ask_channel.relayd_id = relayd_id;
 	msg->u.ask_channel.key = key;
 	msg->u.ask_channel.chan_id = chan_id;
+	msg->u.ask_channel.tracefile_size = tracefile_size;
+	msg->u.ask_channel.tracefile_count = tracefile_count;
+	msg->u.ask_channel.monitor = monitor;
+	msg->u.ask_channel.ust_app_uid = ust_app_uid;
 
 	memcpy(msg->u.ask_channel.uuid, uuid, sizeof(msg->u.ask_channel.uuid));
 
-	strncpy(msg->u.ask_channel.pathname, pathname,
-			sizeof(msg->u.ask_channel.pathname));
-	msg->u.ask_channel.pathname[sizeof(msg->u.ask_channel.pathname)-1] = '\0';
+	if (pathname) {
+		strncpy(msg->u.ask_channel.pathname, pathname,
+				sizeof(msg->u.ask_channel.pathname));
+		msg->u.ask_channel.pathname[sizeof(msg->u.ask_channel.pathname)-1] = '\0';
+	}
 
 	strncpy(msg->u.ask_channel.name, name, sizeof(msg->u.ask_channel.name));
 	msg->u.ask_channel.name[sizeof(msg->u.ask_channel.name) - 1] = '\0';
@@ -709,7 +853,11 @@ void consumer_init_channel_comm_msg(struct lttcomm_consumer_msg *msg,
 		const char *name,
 		unsigned int nb_init_streams,
 		enum lttng_event_output output,
-		int type)
+		int type,
+		uint64_t tracefile_size,
+		uint64_t tracefile_count,
+		unsigned int monitor,
+		unsigned int live_timer_interval)
 {
 	assert(msg);
 
@@ -726,6 +874,10 @@ void consumer_init_channel_comm_msg(struct lttcomm_consumer_msg *msg,
 	msg->u.channel.nb_init_streams = nb_init_streams;
 	msg->u.channel.output = output;
 	msg->u.channel.type = type;
+	msg->u.channel.tracefile_size = tracefile_size;
+	msg->u.channel.tracefile_count = tracefile_count;
+	msg->u.channel.monitor = monitor;
+	msg->u.channel.live_timer_interval = live_timer_interval;
 
 	strncpy(msg->u.channel.pathname, pathname,
 			sizeof(msg->u.channel.pathname));
@@ -754,6 +906,19 @@ void consumer_init_stream_comm_msg(struct lttcomm_consumer_msg *msg,
 	msg->u.stream.cpu = cpu;
 }
 
+void consumer_init_streams_sent_comm_msg(struct lttcomm_consumer_msg *msg,
+		enum lttng_consumer_command cmd,
+		uint64_t channel_key, uint64_t net_seq_idx)
+{
+	assert(msg);
+
+	memset(msg, 0, sizeof(struct lttcomm_consumer_msg));
+
+	msg->cmd_type = cmd;
+	msg->u.sent_streams.channel_key = channel_key;
+	msg->u.sent_streams.net_seq_idx = net_seq_idx;
+}
+
 /*
  * Send stream communication structure to the consumer.
  */
@@ -768,16 +933,7 @@ int consumer_send_stream(struct consumer_socket *sock,
 	assert(sock);
 	assert(fds);
 
-	/* Send on socket */
-	ret = lttcomm_send_unix_sock(sock->fd, msg,
-			sizeof(struct lttcomm_consumer_msg));
-	if (ret < 0) {
-		/* The above call will print a PERROR on error. */
-		DBG("Error when sending consumer stream on sock %d", sock->fd);
-		goto error;
-	}
-
-	ret = consumer_recv_status_reply(sock);
+	ret = consumer_send_msg(sock, msg);
 	if (ret < 0) {
 		goto error;
 	}
@@ -797,14 +953,15 @@ error:
  * On success return positive value. On error, negative value.
  */
 int consumer_send_relayd_socket(struct consumer_socket *consumer_sock,
-		struct lttcomm_sock *sock, struct consumer_output *consumer,
-		enum lttng_stream_type type, uint64_t session_id)
+		struct lttcomm_relayd_sock *rsock, struct consumer_output *consumer,
+		enum lttng_stream_type type, uint64_t session_id,
+		char *session_name, char *hostname, int session_live_timer)
 {
 	int ret;
 	struct lttcomm_consumer_msg msg;
 
 	/* Code flow error. Safety net. */
-	assert(sock);
+	assert(rsock);
 	assert(consumer);
 	assert(consumer_sock);
 
@@ -814,6 +971,18 @@ int consumer_send_relayd_socket(struct consumer_socket *consumer_sock,
 		goto error;
 	}
 
+	if (type == LTTNG_STREAM_CONTROL) {
+		ret = relayd_create_session(rsock,
+				&msg.u.relayd_sock.relayd_session_id,
+				session_name, hostname, session_live_timer,
+				consumer->snapshot);
+		if (ret < 0) {
+			/* Close the control socket. */
+			(void) relayd_close(rsock);
+			goto error;
+		}
+	}
+
 	msg.cmd_type = LTTNG_CONSUMER_ADD_RELAYD_SOCKET;
 	/*
 	 * Assign network consumer output index using the temporary consumer since
@@ -823,23 +992,16 @@ int consumer_send_relayd_socket(struct consumer_socket *consumer_sock,
 	msg.u.relayd_sock.net_index = consumer->net_seq_index;
 	msg.u.relayd_sock.type = type;
 	msg.u.relayd_sock.session_id = session_id;
-	memcpy(&msg.u.relayd_sock.sock, sock, sizeof(msg.u.relayd_sock.sock));
+	memcpy(&msg.u.relayd_sock.sock, rsock, sizeof(msg.u.relayd_sock.sock));
 
-	DBG3("Sending relayd sock info to consumer on %d", consumer_sock->fd);
-	ret = lttcomm_send_unix_sock(consumer_sock->fd, &msg, sizeof(msg));
-	if (ret < 0) {
-		/* The above call will print a PERROR on error. */
-		DBG("Error when sending relayd sockets on sock %d", sock->fd);
-		goto error;
-	}
-
-	ret = consumer_recv_status_reply(consumer_sock);
+	DBG3("Sending relayd sock info to consumer on %d", *consumer_sock->fd_ptr);
+	ret = consumer_send_msg(consumer_sock, &msg);
 	if (ret < 0) {
 		goto error;
 	}
 
 	DBG3("Sending relayd socket file descriptor to consumer");
-	ret = consumer_send_fds(consumer_sock, &sock->fd, 1);
+	ret = consumer_send_fds(consumer_sock, &rsock->sock.fd, 1);
 	if (ret < 0) {
 		goto error;
 	}
@@ -926,15 +1088,9 @@ int consumer_is_data_pending(uint64_t session_id,
 	rcu_read_lock();
 	cds_lfht_for_each_entry(consumer->socks->ht, &iter.iter, socket,
 			node.node) {
-		/* Code flow error */
-		assert(socket->fd >= 0);
-
 		pthread_mutex_lock(socket->lock);
-
-		ret = lttcomm_send_unix_sock(socket->fd, &msg, sizeof(msg));
+		ret = consumer_socket_send(socket, &msg, sizeof(msg));
 		if (ret < 0) {
-			/* The above call will print a PERROR on error. */
-			DBG("Error on consumer is data pending on sock %d", socket->fd);
 			pthread_mutex_unlock(socket->lock);
 			goto error_unlock;
 		}
@@ -944,18 +1100,11 @@ int consumer_is_data_pending(uint64_t session_id,
 		 * the reply status message.
 		 */
 
-		ret = lttcomm_recv_unix_sock(socket->fd, &ret_code, sizeof(ret_code));
-		if (ret <= 0) {
-			if (ret == 0) {
-				/* Orderly shutdown. Don't return 0 which means success. */
-				ret = -1;
-			}
-			/* The above call will print a PERROR on error. */
-			DBG("Error on recv consumer is data pending on sock %d", socket->fd);
+		ret = consumer_socket_recv(socket, &ret_code, sizeof(ret_code));
+		if (ret < 0) {
 			pthread_mutex_unlock(socket->lock);
 			goto error_unlock;
 		}
-
 		pthread_mutex_unlock(socket->lock);
 
 		if (ret_code == 1) {
@@ -984,7 +1133,6 @@ int consumer_flush_channel(struct consumer_socket *socket, uint64_t key)
 	struct lttcomm_consumer_msg msg;
 
 	assert(socket);
-	assert(socket->fd >= 0);
 
 	DBG2("Consumer flush channel key %" PRIu64, key);
 
@@ -1017,7 +1165,6 @@ int consumer_close_metadata(struct consumer_socket *socket,
 	struct lttcomm_consumer_msg msg;
 
 	assert(socket);
-	assert(socket->fd >= 0);
 
 	DBG2("Consumer close metadata channel key %" PRIu64, metadata_key);
 
@@ -1050,7 +1197,6 @@ int consumer_setup_metadata(struct consumer_socket *socket,
 	struct lttcomm_consumer_msg msg;
 
 	assert(socket);
-	assert(socket->fd >= 0);
 
 	DBG2("Consumer setup metadata channel key %" PRIu64, metadata_key);
 
@@ -1072,7 +1218,7 @@ end:
 }
 
 /*
- * Send metadata string to consumer.
+ * Send metadata string to consumer. Socket lock MUST be acquired.
  *
  * Return 0 on success else a negative value.
  */
@@ -1084,32 +1230,24 @@ int consumer_push_metadata(struct consumer_socket *socket,
 	struct lttcomm_consumer_msg msg;
 
 	assert(socket);
-	assert(socket->fd >= 0);
 
-	DBG2("Consumer push metadata to consumer socket %d", socket->fd);
+	DBG2("Consumer push metadata to consumer socket %d", *socket->fd_ptr);
 
 	msg.cmd_type = LTTNG_CONSUMER_PUSH_METADATA;
 	msg.u.push_metadata.key = metadata_key;
 	msg.u.push_metadata.target_offset = target_offset;
 	msg.u.push_metadata.len = len;
 
-	/*
-	 * TODO: reenable these locks when the consumerd gets the ability to
-	 * reorder the metadata it receives. This fits with locking in
-	 * src/bin/lttng-sessiond/ust-app.c:push_metadata()
-	 *
-	 * pthread_mutex_lock(socket->lock);
-	 */
-
 	health_code_update();
 	ret = consumer_send_msg(socket, &msg);
-	if (ret < 0) {
+	if (ret < 0 || len == 0) {
 		goto end;
 	}
 
-	DBG3("Consumer pushing metadata on sock %d of len %lu", socket->fd, len);
+	DBG3("Consumer pushing metadata on sock %d of len %zu", *socket->fd_ptr,
+			len);
 
-	ret = lttcomm_send_unix_sock(socket->fd, metadata_str, len);
+	ret = consumer_socket_send(socket, metadata_str, len);
 	if (ret < 0) {
 		goto end;
 	}
@@ -1122,8 +1260,75 @@ int consumer_push_metadata(struct consumer_socket *socket,
 
 end:
 	health_code_update();
-	/*
-	 * pthread_mutex_unlock(socket->lock);
-	 */
+	return ret;
+}
+
+/*
+ * Ask the consumer to snapshot a specific channel using the key.
+ *
+ * Return 0 on success or else a negative error.
+ */
+int consumer_snapshot_channel(struct consumer_socket *socket, uint64_t key,
+		struct snapshot_output *output, int metadata, uid_t uid, gid_t gid,
+		const char *session_path, int wait, int max_stream_size)
+{
+	int ret;
+	struct lttcomm_consumer_msg msg;
+
+	assert(socket);
+	assert(output);
+	assert(output->consumer);
+
+	DBG("Consumer snapshot channel key %" PRIu64, key);
+
+	memset(&msg, 0, sizeof(msg));
+	msg.cmd_type = LTTNG_CONSUMER_SNAPSHOT_CHANNEL;
+	msg.u.snapshot_channel.key = key;
+	msg.u.snapshot_channel.max_stream_size = max_stream_size;
+	msg.u.snapshot_channel.metadata = metadata;
+
+	if (output->consumer->type == CONSUMER_DST_NET) {
+		msg.u.snapshot_channel.relayd_id = output->consumer->net_seq_index;
+		msg.u.snapshot_channel.use_relayd = 1;
+		ret = snprintf(msg.u.snapshot_channel.pathname,
+				sizeof(msg.u.snapshot_channel.pathname),
+				"%s/%s-%s-%" PRIu64 "%s", output->consumer->subdir,
+				output->name, output->datetime, output->nb_snapshot,
+				session_path);
+		if (ret < 0) {
+			ret = -LTTNG_ERR_NOMEM;
+			goto error;
+		}
+	} else {
+		ret = snprintf(msg.u.snapshot_channel.pathname,
+				sizeof(msg.u.snapshot_channel.pathname),
+				"%s/%s-%s-%" PRIu64 "%s", output->consumer->dst.trace_path,
+				output->name, output->datetime, output->nb_snapshot,
+				session_path);
+		if (ret < 0) {
+			ret = -LTTNG_ERR_NOMEM;
+			goto error;
+		}
+		msg.u.snapshot_channel.relayd_id = (uint64_t) -1ULL;
+
+		/* Create directory. Ignore if exist. */
+		ret = run_as_mkdir_recursive(msg.u.snapshot_channel.pathname,
+				S_IRWXU | S_IRWXG, uid, gid);
+		if (ret < 0) {
+			if (ret != -EEXIST) {
+				ERR("Trace directory creation error");
+				goto error;
+			}
+		}
+	}
+
+	health_code_update();
+	ret = consumer_send_msg(socket, &msg);
+	if (ret < 0) {
+		goto error;
+	}
+
+error:
+	health_code_update();
 	return ret;
 }